Raymond eugene powell



Feb. 25, 1930,

Original Filed May 22, 1926 /m ema r V I fla molrdff Panel Reissued Feb.25, 1930 UNITED STATES PATENT OFFICE RAYMOND EUGENE POWELL, OFWESTFIELD, NEW JERSEY, ASS IGNOR TO WESTERN ELECTRIC COMPANY,INCORPORATED, OF NEW YORK, N. Y., A. CORPORATION OF NEW YORK RESISTANCEWELDING ELECTRODE Original No. 1,673,020, dated June 12, 1928, Seria1No. 110,905, filed May 22, 1926. Application for reissue filed April 22,1929.

This invention relates to welding apparatus, and more particularly toelectrodes and electrode holders for use in electrical resist anceWelding.

In some instances in welding by the electrical resistance method, partsto be welded are so designed and proportioned-as to render it diflicultto produce a weld in the desired position without causing contactsbetween the parts and the electrode or holder therefor atpoints otherthan the location of the weld. These additional contacts may result inthe fusing of the work at these points as well as cause a diversion of asufiicient amount of the welding current from the tipof the electrode tomaterially reduce the eifectiveness of the welding operation.

An object of the invention is to provide a simplified apparatus forelectrically welding parts wherein the current conducting portions areelectrically insulated from the parts except at the position of theweld.

In accordance with one embodiment of the invention, the elect-rode andthe holder therefor are each surrounded by a band of steel which hasbeen treated with a solution of phosphoric acid, changingthe surface ofthe steel to adull' black phosphate of iron which is a good electricinsulator underthe severe temperature and other conditions encounteredin welding. Y It is believed that a complete understanding of theinvention may be had by reference to the following description taken inconjunction with the accompanying drawing which illustrates oneembodiment of the invention.

The drawing illustrates the application of electrode units 1 and 2 tothe welding of parts of a wall assen'ibly for a loading coil case, suchas is used extensively in telephone transmission circuits, in which anangularly shaped piece 4 is welded to a cylindrical surface 5 Thewelding current in a resistance weldingprocessirisome cases isregulatedto the exact amount required to produce a weld in the material betweenthe electrodes. If therefore, the lateral surfaces of the electrode orits holder come in contact with the work, some of the current will bediverted and there may Serial No. 357,263.

be insufficient current flowing from the tips of the electrodes throughthe parts to be welded to form an entirely satisfactory. weld. Ac

cording to the present invention, copper elec-.

trodes 6 and electrode holders? of any usual type andassociated with asuitable electrical welding circuit (not shown), are surrounded by steelbands-or jackets S which have been previously treated in a solution ofphosphoric acid changing the surface of the steel to a dull blackphosphate of iron, thus forming a layer of electrical insulatingmaterial on the surfaces of the steel band. Thus the bands whichpreferably are pressed over the electrodes and the holders form aninsulating sheath around these parts preventing a diversion of thewelding current through coiicomprising an electrode provided with aninsulating acket having a coating of phosphate of iron, and anelectrodei holder provided 'with' an insulating jacket having a coatingof phosphate of iron.

2. An electrode unit for electric welding comprising an electrodesurrounded by a band of steel having a phosphate of iron surface, and anelectrode holder surrounded by a band of steel having a phosphate ofiron surface.

3. In an electrode unit for electric welding an electrode having aninsulating material of phosphate of iron on a surface thereof.

4. In an electrode unit for electric welding an electrode provided withan insulating j ackethaving a coatingof phosphate of iron.

5. In an electrode unit for electric welding an electrode surrounded bya band of steel having a phosphate of iron surface.

6. An electrical current-carrying member. having an insulating coatingof phosphate of iron.

7. In combination, a member designed to 5 conduct electrical current,and an insulating coating of phosphate of iron on a surface of themember. s

8. 'An electrical current-carrying member,

and a ferrous member attached thereto and having a coating of phosphateof iron to provide an insulation for the current-carrying member; s

9. Anelectrical current-carrying member, and 'a protective membersurrounding the first mentioned member and having a coating of phosphateof iron thereon.

10. An electrical conductor designed to carry heavy electrical currents,at least. a portion of the conductor being formed of fer- 0 rous metal,and an autogenous coating of iron phosphate formed onsaid portion.

1laAn electrical conductor designed to carry heavy electrical currentsand to be subjected to high temperatures during use and an insulatingcoating of iron phosphate on the conductor. 2

12. In electrical apparatus, a member formed of electrically conductiveferrous material and having an autogenous insulata0 ing coating of ironphosphate thereon.

13. In electrical apparatus, a member formed of electrically conductivematerial and having an insulating coating of iron phosphate thereon. 1

In Witness whereof, I hereunto subscribe my name this 15th (lay of AprilA. D. 1929.

RAYMOND EUGENE POWELL.

